Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Minichromosome Maintenance Complex Component 4”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1996

Fission yeast cdc21, a member of the MCM protein family, is required for onset of S phase and is located in the nucleus throughout the cell cycle.

The fission yeast cdc21 protein belongs to the MCM family, implicated in the once per cell cycle regulation of chromosome replication. In budding yeast, proteins in this family are eliminated from the nucleus during S phase, which has led to the suggestion that they may serve to distinguish unreplicated from replicated DNA, as in the licensing factor model. We show here that, in contrast to the situation in budding yeast, cdc21 remains in the nucleus after S phase, as is found for related proteins in mammalian cells. We suggest that regulation of nuclear import of these proteins may not be an essential aspect of their function in chromosome replication. To determine the function of cdc21+, we have analysed the phenotype of a gene deletion. cdc21+ is required for entry into S phase and, unexpectedly, a proportion of cells depleted of the gene product are able to enter mitosis in the absence of DNA replication. These results are consistent with the view that individual proteins in the MCM family are required for all initiation events, and defective initiation may impair the coordination between mitosis and S phase.

Animals↗
PubMed2001

Human DNA replication initiation factors, ORC and MCM, associate with oriP of Epstein-Barr virus.

The 165-kb chromosome of Epstein-Barr virus (EBV) is replicated by cellular enzymes only once per cell cycle in human cells that are latently infected. Here, we report that the human origin recognition complex, ORC, can be detected in association with an EBV replication origin, oriP, in cells by using antibodies against three different subunits of human ORC to precipitate crosslinked chromatin. Mcm2, a subunit of the MCM replication licensing complex, was found to associate with oriP during G(1) and to dissociate from it during S phase. The detection of ORC and Mcm2 at oriP was shown to require the presence of the 120-bp replicator of oriP. Licensing and initiation of replication at oriP of EBV thus seem to be mediated by ORC. This is an example of a virus apparently using ORC and associated factors for the propagation of its genome.

Cell Cycle↗
PubMed2003

Conditional expression of MCM7 increases tumor growth without altering DNA replication activity.

The minichromosome maintenance (MCM) 2-7 complex is a putative DNA helicase complex that facilitates the initiation of DNA replication. Here, we generated a cell line MCM7(+/-)/MCM7-FLAG, in which one allele of MCM7 is mutated whereas a tetracycline-repressible promoter could manipulate the expression of exogenous MCM7 protein. Overexpressed MCM7 protein supports efficient DNA replication of Epstein-Barr virus oriP and rapid formation of tumors in nude mice without altering the activity of cellular DNA replication. This system provides a unique setting for studying the function of MCM7 and for screening for potential therapeutics for malignant tumors.

Animals↗
PubMed1999

The RLF-B component of the replication licensing system is distinct from Cdc6 and functions after Cdc6 binds to chromatin.

Replication licensing factor (RLF) is an essential initiation factor that can prevent re-replication of DNA in a single cell cycle [1] [2]. It is required for the initiation of DNA replication, binds to chromatin early in the cell cycle, is removed from chromatin as DNA replicates and is unable to re-bind replicated chromatin until the following mitosis. Chromatography of RLF from Xenopus extracts has shown that it consists of two components termed RLF-B and RLF-M [3]. The RLF-M component consists of complexes of all six Xenopus minichromosome maintenance (MCM/P1) proteins (XMcm2-7), which bind to chromatin in late mitosis and are removed as replication occurs [3] [4] [5] [6] [7]. The identity of RLF-B is currently unknown. At least two factors must be present on chromatin before licensing can occur: the Xenopus origin recognition complex (XORC) [8] [9] and Xenopus Cdc6 (XCdc6) [10]. XORC saturates Xenopus sperm chromatin at approximately one copy per replication origin whereas XCdc6 binds to chromatin only if XORC is bound first [9] [10] [11]. Although XORC has been shown to be a distinct activity from RLF-B [9], the relationship between XCdc6 and RLF-B is currently unclear. Here, we show that active XCdc6 is loaded onto chromatin in extracts with defective RLF, and that both RLF-M and RLF-B are still required for the licensing of XCdc6-containing chromatin. Furthermore, RLF-B can be separated from XCdc6 by immunoprecipitation and standard chromatography. These experiments demonstrate that RLF-B is both functionally and physically distinct from XCdc6, and that XCdc6 is loaded onto chromatin before RLF-B function is executed.

Animals↗
PubMed2003

The cyclin D1-dependent kinase associates with the pre-replication complex and modulates RB.MCM7 binding.

The capacity of the cyclin D-dependent kinase to promote G(1) progression through modulation of RB.E2F is well documented. We now demonstrate that the cyclin D1/CDK4 kinase binds to components of the MCM complex. MCM7 and MCM3 were identified as cyclin D1-binding proteins. Catalytically active cyclin D1/CDK4 complexes were incorporated into chromatin-bound protein complexes with the same kinetics as MCM7 and MCM3, where they associated specifically with MCM7. Although the cyclin D1-dependent kinase did not phosphorylate MCM7, active cyclin D1/CDK4, but not cyclin E/CDK2, did catalyze the dissociation of an RB.MCM7 complex. Finally, expression of an active D1/CDK4 kinase but not cyclin E/CDK2 promoted the removal of RB from chromatin-bound protein complexes. Our data suggest that D1/CDK4 complexes play a direct role in altering an inhibitory RB.MCM7 complex possibly allowing for setting of the origin in preparation for DNA replication.

3T3 Cells↗
PubMed2000

Identification of functional PDZ domain binding sites in several human proteins.

TIP-15 was previously identified as a cellular protein that can bind to the C-terminal end of the HTLV-1 Tax protein via its two PDZ domains. The sequence of the N-terminal part of TIP-15 is identical to that of the synaptic protein PSD-95. Both proteins are likely to be produced from the same gene by alternative splicing. Whereas expression of the PSD-95 mRNA was detected only with brain RNAs, that of TIP-15 was detected with RNAs from thymus, brain, skeletal muscle and Jurkat cells. The TIP-15 protein exhibits an apparent molecular weight of 40 kD and is weakly expressed in T cell lines. A two-hybrid screen performed with TIP-15 as bait revealed the presence of a PDZ binding site (PDZ-BS) in the following proteins: Lysyl tRNA synthetase, 6-phosphogluconolactonase (6-GPL), Stress-activated protein kinase 3 (SAPK3), NET-1, Diacylglycerol kinase zeta, MTMR1, MCM7, and hSec8. The sequence at the C-terminal ends of these proteins matches the X-S/T-X-V-COOH consensus previously defined for PDZ-BSs, with the exception of 6-GPL and SAPK3 which include a leucine as the C-terminal residue. For Lysyl tRNA synthetase, NET1, MTMR1 and hSec8, binding to TIP-15 was confirmed by co-immunoprecipitation experiments performed with the extracts of transfected COS7 cells. These results show the existence of functional PDZ-BSs in these proteins, but future studies will be necessary to establish whether or not TIP-15 represents a physiological partner. The significance of the presence of a PDZ-BS in these various proteins is discussed with respect to their function.

Amino Acid Sequence↗
PubMed2006

Identification of biomarkers that distinguish human papillomavirus (HPV)-positive versus HPV-negative head and neck cancers in a mouse model.

Head and neck squamous cell carcinoma (HNSCC) is a leading cause of cancer mortality worldwide. Recent reports have associated a subset of HNSCC with high-risk human papillomaviruses (HPVs), particularly HPV16, the same subset of HPVs responsible for the majority of cervical and anogenital cancers. In this study we describe a mouse model for HPV-associated HNSCC that employs mice transgenic for the HPV16 oncogenes E6 and E7. In these mice, E6 and E7 induce aberrant epithelial proliferation and, in the presence of a chemical carcinogen, they increase dramatically the animal's susceptibility to HNSCC. The cancers arising in the HPV16-transgenic mice mirror the molecular and histopathological characteristics of human HPV-positive HNSCC that distinguish the latter from human HPV-negative HNSCC, including overexpression of p16 protein and formation of more basaloid cancers. This validated model of HPV-associated HNSCC provides the means to define the contributions of individual HPV oncogenes to HNSCC and to understand the molecular basis for the differing clinical properties of HPV-positive and HPV-negative human HNSCC. From this study, we identify minichromosome maintenance protein 7 (MCM7) and p16 as potentially useful biomarkers for HPV-positive head and neck cancer.

4-Nitroquinoline-1-oxide↗
PubMed2003

Budding yeast mcm10/dna43 mutant requires a novel repair pathway for viability.

BACKGROUND: MCM10 is essential for the initiation of chromosomal DNA replication in Saccharomyces cerevisiae. Mcm10p functionally interacts with components of the pre-replicative complex (Mcm2-Mcm7 complex and origin recognition complex) as well as the pre-initiation complex component (Cdc45p) suggesting that it may be a component of the pre-RC as well as the pre-IC. Two-dimensional gel electrophoresis analysis showed that Mcm10p is required not only for the initiation of DNA synthesis at replication origins but also for the smooth passage of replication forks at origins. Genetic analysis showed that MCM10 interacts with components of the elongation machinery such as Pol delta and Pol epsilon, suggesting that it may play a role in elongation replication. RESULTS: We show that the mcm10 mutation causes replication fork pausing not only at potentially active origins but also at silent origins. We screened for mutations that are lethal in combination with mcm10-1 and obtained seven mutants named slm1-slm6 for synthetically lethal with mcm10. These mutants comprised six complementation groups that can be divided into three classes. Class 1 includes genes that encode components of the pre-RC and pre-IC and are represented by SLM3, 4 and 5 which are allelic to MCM7, MCM2 and CDC45, respectively. Class 2 includes genes involved in the processing of Okazaki fragments in lagging strand synthesis and is represented by SLM1, which is allelic to DNA2. Class 3 includes novel DNA repair genes represented by SLM2 and SLM6. CONCLUSIONS: The viability of the mcm10-1 mutant is dependent on a novel repair pathway that may participate either in resolving accumulated replication intermediates or the damage caused by blocked replication forks. These results are consistent with the hypothesis that Mcm10p is required for the passage of replication forks through obstacles such as those created by pre-RCs assembled at active or inactive replication origins.

Carrier Proteins↗
PubMed2000

Interactions between Mcm10p and other replication factors are required for proper initiation and elongation of chromosomal DNA replication in Saccharomyces cerevisiae.

BACKGROUND: MCM10 is essential for the initiation of chromosomal DNA replication in Saccharomyces cerevisiae. Previous work showed that Mcm10p interacts with the Mcm2-7 protein complex that may be functioning as the replication-licensing factor. In addition, Mcm10p is required during origin activation and disassembly of the prereplicative complex, which allows smooth passage of replication forks. RESULTS: We show that an mcm10 mutation causes a slow progression of DNA synthesis and a loss of chromosome integrity during the S phase and prevents entry into mitosis, despite apparent completion of chromosomal DNA replication at nonpermissive temperatures. Furthermore, Mcm10p interacts genetically with the origin recognition complex (ORC) and various replication elongation factors, including a subunit of DNA polymerases epsilon and delta. Mcm10p is an abundant protein (approximately 4 x 10(4) copies per haploid cell) that is almost exclusively localized in the chromatin and/or nuclear matrix fractions during all phases of the cell cycle. When it is visualized by the chromosome-spreading method followed by immunostaining, Mcm10p forms punctate foci on chromatin throughout the cell cycle and these foci mostly overlap with those of Orc1p, a component of ORC. CONCLUSIONS: These results suggest that Mcm10p, like the Mcm2-7 proteins, is a critical component of the prereplication chromatin and acts together with ORC during the initiation of chromosomal DNA replication; in addition, Mcm10p plays an important role during the elongation of DNA replication.

Cell Cycle Proteins↗
PubMed1999

Identification and complete cDNA sequence of the missing Drosophila MCMs: DmMCM3, DmMCM6 and DmMCM7.

The minichromosome maintenance (MCM) gene family consists of six members (MCM2, 3, 4, 5, 6 and 7) in Saccharomyces cerevisiae as well as in humans. Each family member plays an essential role in the replication of DNA. In Drosophila melanogaster only three members, DmMCM2, DmMCM4/dpa and DmMCM5/DmCDC46, have been studied. In addition, two other partial sequences were recently reported. Using degenerate primers and low stringency PCR conditions six different DNA sequences were identified with highest sequence similarity to MCM2, 3, 4, 5, 6 and 7. Sequence analysis of full length cDNA clones corresponding to the MCM3, 6 and 7 fragment proves the existence of six MCM genes in Drosophila melanogaster. Strong homology to the human counterparts, mRNA expression analysis and physico-chemical properties suggest a conserved function in DNA replication for DmMCM3, 6 and 7.

Amino Acid Sequence↗
PubMed2003

Minichromosome maintenance 2 expression is correlated with mode of invasion and prognosis in oral squamous cell carcinomas.

BACKGROUND: This study examined the immunohistochemical expression of cell-cycle related molecules as well as cell proliferation and pathologic findings in oral squamous cell carcinoma (SCC) in order to clarify their pathobiologic and prognostic significance. METHODS: A total of 46 oral SCC specimens were analyzed using Ki-67, minichromosome maintenance 2 (MCM2), p53, p27, p21, and TUNEL. Aspects including tumor differentiation, mode of carcinoma invasion, tumor metastasis, and patient prognosis were compared among the specimens. RESULTS: A significantly higher MCM2 labeling index (LI) was observed in the moderately differentiated SCCs when compared to the well-differentiated SCCs (P<0.05). The higher MCM2 LI was correlated with mode of invasion Grade 4 (infiltrative growth) and patient prognosis. In contrast, the LIs of Ki-67, TUNEL-signal, p53, p27, and p21 were not correlated with patient prognosis. CONCLUSION: Higher MCM2 LI provides useful information for patient prognosis in oral SCCs.

Carcinoma, Squamous Cell↗
PubMed2005

Relation between hepatocyte G1 arrest, impaired hepatic regeneration, and fibrosis in chronic hepatitis C virus infection.

BACKGROUNDS & AIMS: An increased risk of hepatitis C virus (HCV)-related cirrhosis is associated with hepatic steatosis, older age, and high alcohol consumption, which could be explained by synergistic effects on cell proliferation. We aimed to investigate hepatocyte cell cycle state and phase distribution in chronic HCV infection. METHODS: Liver biopsy specimens diagnostic for chronic HCV (70), liver regeneration following transplant-related ischemic-reperfusion injury (15), and "normal" liver adjacent to colorectal cancer metastasis (10) were studied. Immunohistochemistry was used to detect cell cycle phase markers cyclin D1 (maximal in G 1 ), cyclin A (S), cyclin B1 (cytoplasmic during G 2 ) and phosphorylated histone 3 protein (mitosis), mini-chromosome maintenance protein 2 (Mcm-2; present throughout the cell cycle), and cyclin-dependent kinase inhibitor p21, which inhibits G 1 /S progression. RESULTS: Hepatocyte Mcm-2 expression was elevated in chronic HCV and liver regeneration (13% vs 26.4%) but negligible in "normal" liver. In proportion to Mcm-2, there was no difference in cyclin D1 between chronic HCV infection and liver regeneration (51.6% of Mcm-2-positive hepatocytes vs 52.6%). In contrast, there was a striking reduction in cyclin A (3% vs 16.3%), cyclin B1 (.4% vs 2.3%), and phosphorylated histone 3 protein (0% vs 3.8%) in chronic HCV infection compared with liver regeneration. In chronic HCV infection, Mcm-2 and p21 expression were associated with fibrosis stage and positive serum HCV RNA. CONCLUSIONS: The data are consistent with hepatocyte G 1 arrest in chronic HCV infection. This could impair hepatocellular function and limit hepatic regeneration.

Adolescent↗
PubMed2001

Biochemical activities associated with mouse Mcm2 protein.

Mcm2, a member of the Mcm2-7 protein family essential for the initiation of DNA replication, has several biochemical activities including the ability to inhibit the Mcm4,6,7 helicase. In this study, we characterized the activities associated with Mcm2 and determined the region required for them. It was found that Mcm2 deleted at an amino-terminal portion is able to bind to an Mcm4,6,7 hexameric complex and to inhibit its DNA helicase activity. The same deletion mutant of Mcm2 and the carboxyl-terminal half of Mcm2 were both able to bind to Mcm4, suggesting that the carboxyl-half of Mcm2 binds to Mcm4 to disassemble the Mcm4,6,7 hexamer. Phosphorylation of Mcm2,4,6,7 complexes with Cdc7 kinase showed that the amino-terminal region of Mcm2 is required for the phosphorylation, and it contains major Cdc7-mediated phosphorylation sites. We also found that Mcm2 itself can assemble a nucleosome-like structure in vitro in the presence of H3/H4 histones. The amino-terminal region of Mcm2 was required for the activity where a histone-binding domain is located. Finally, we identified a region required for the nuclear localization of Mcm2. The function of Mcm2 is discussed based on these biochemical characteristics.

Amino Acid Sequence↗
PubMed1998

Protein kinase inhibition in G2 causes mammalian Mcm proteins to reassociate with chromatin and restores ability to replicate.

Intact nuclei from G2-phase mammalian cells will replicate their DNA in Xenopus egg extract if they are preexposed to the protein kinase inhibitor 6-dimethylaminopurine in vivo (Coverley et al., Exp. Cell Res. 225, 294-300, 1996). Here, we demonstrate that this competence to rereplicate is accompanied by alterations in the subcellular distribution of the Mcm family of proteins, which are implicated in replication licensing (Hennessy et al., Genes Dev. 4, 2252-2263, 1990; Kubota et al., Cell 81, 601-609, 1995; and Chong et al., Nature 375, 418-421, 1995). All family members reassociate with chromatin in G2 cells and this correlates closely with regeneration of replication competence. Moreover, newly bound Mcm proteins are functional for replication because, unlike untreated G2 nuclei, replication of treated G2 nuclei in vitro occurs independent of the Xenopus Mcm protein complex. These observations show that the postreplicative state is actively maintained in G2 cells by a protein kinase(s) which regulates the behavior of Mcm family proteins.

Adenine↗
PubMedDate not supplied

Phyllodes tumor of the breast: EGFR family expression and relation to clinicopathological features.

The expression of EGFR family members was examined by immunohistochemistry in 22 phyllodes tumors, and the results were evaluated together with immunohistochemical findings for proliferation markers Ki67 and BM28, and the tumor suppressor gene product p53. Light and electron microscopy were performed in all cases. Clinical information was obtained from the medial records. We did find that expression of EG FR, c-erbB-3 and c-erbB-4 proteins could be detected in the neoplastic mesenchymal cells, and that the expression increased with increasing malignancy. Increased expressions of Ki67, BM28, p53 and EGFR family members in neoplastic cells were associated with malignancy and unfavorable clinical course. Furthermore, the expression of ER-alpha and PR in the epithelial cells of phyllodes tumors was increased compared to that in normal breast epithelium. Finally, the application of electron microscopy helped to identify a group of malignant tumors, revealing neoplastic cells with characteristic nuclear indentations, as well as an increasing number of myofibroblasts.

Adolescent↗
PubMed2004

Correlation of MYCN amplification with MCM7 protein expression in neuroblastomas: a chromogenic in situ hybridization study in paraffin sections.

Amplification of the MYCN oncogene in neuroblastomas is generally associated with a more aggressive clinical course. Recently, 1 of the minichromosome maintenance proteins, MCM7, was found to be a direct target of the MYCN transcription factor in neuroblastoma. To confirm this correlation, chromogenic in situ hybridization (CISH) to detect MYCN amplification and immunohistochemical staining for MCM7 protein expression were performed on paraffin tissue sections of 26 neuroblastomas cases and of 4 recurrences of these tumors. Seven of the primary tumors showed MYCN amplification, and all were stage 3 or 4 tumors. Only 4 of these showed MCM7 overexpression. However, 11 primary tumors overexpressed MCM7. The 4 patients with MCM7 expression associated with MYCN amplification all died from the tumor. In contrast, the 7 patients with MCM7 overexpression but no MYCN amplification were all younger than 1 year of age and have shown good survival. This suggests that MCM7 overexpression by itself is not related to a poorer prognosis as is MYCN amplification. In addition, the 4 pairs of primary and recurrent tumors all showed changes in MCM7 expression from negative to positive, whereas none of them had MYCN amplification. This study showed that MCM7 overexpression is not necessarily correlated with MYCN amplification or an aggressive clinical course. Interpretation of the results of CISH was quite easy and straightforward because the preparations were viewed with an ordinary light microscope with good preservation of the tissue morphology.

Adolescent↗
PubMed2006

Replication competence and senescence in central and peripheral human corneal endothelium.

PURPOSE: To compare replication competence and senescence in human corneal endothelial cells (HCECs) between the central and peripheral areas and between younger and older donors. METHODS: Human corneas were obtained from the eye bank and separated into two groups: young (younger than 30 years) and old (older than 50 years). Corneas were cut in quarters and a 2-mm scrape wound was created in the endothelium from the periphery to the center. Unwounded endothelium acted as a negative control. Corneal pieces were incubated for 24, 36, 48, 60, 72, 84, and 96 hours in medium containing 8% fetal bovine serum (FBS) plus additional growth factors. Tissue was fixed, immunostained for minichromosome maintenance (MCM)-2, a marker of replication competence, and mounted in medium containing propidium iodide (PI) to visualize all nuclei. Fluorescence microscope images were used to count PI-stained and MCM2-positive HCECs in three 100-microm2 areas within the central and peripheral wound area. Results are expressed as mean number of cells/100 microm2. Senescent HCECs in ex vivo corneas were identified by staining for senescence-associated beta-galactosidase activity (SA-beta-Gal). Whole corneas were cut in quarters and incubated in staining solution containing SA-beta-Gal at pH 6.0. The number of cells stained for SA-beta-Gal and the grade of SA-beta-Gal intensity in three 100-microm2 areas were averaged for the central and peripheral areas from each donor. For all studies, results were compared between central and peripheral cornea and between younger and older donors. RESULTS: In both age groups (n = 4/group), cells repopulated the wound area in a time-dependent manner. In corneas from older donors, significantly fewer HCECs migrated into the wound bed in the central cornea than in the periphery. At each time point, the density of cells in the central wound area was lower in corneas from older donors than from younger donors. In both age groups, the mean percentage of MCM2-positive cells increased with time until wound healing. In both age groups, more MCM2-positive cells were present in the wounded area of the peripheral than of the central cornea. At 36, 48, 60, and 72 hours after wounding, the percentage of MCM2-positive cells in the central or peripheral area of older corneas was significantly less than in the corresponding region in younger corneas. No MCM2-positive staining was observed in unwounded areas at any time point. HCECs in corneas from younger donors (n = 4) showed little to no SA-beta-Gal activity in either the central or peripheral area. SA-beta-Gal activity was easily detectable in corneas from older donors (n = 4) and a significantly higher percentage of central HCECs showed strong SA-beta-Gal activity compared with HCECs in the periphery. CONCLUSIONS: In ex vivo corneas, HCECs from the peripheral area retain higher replication competence, regardless of donor age. HCECs in the central area of corneas from older donors retain replicative competence, but the relative percentage of cells that are competent to replicate is significantly lower than in the periphery or in the central area of corneas from younger donors. This reduction in replicative competence negatively correlates with the observed increase in the population of central HCECs exhibiting senescence-like characteristics.

Adolescent↗
PubMed2006

CDC7 kinase phosphorylates serine residues adjacent to acidic amino acids in the minichromosome maintenance 2 protein.

Cdc7 is an essential kinase required for the initiation of eukaryotic DNA replication. Previous studies in many species showed that the minichromosome maintenance complex is a major physiological target of this kinase. In this study, we have mapped the sites in human Mcm2 protein that are phosphorylated by Cdc7. The in vitro phosphorylation of several Mcm2 truncated proteins and peptides revealed that Mcm2 contains two major ((5)S and (53)S) and at least three minor phosphorylation sites ((4)S, (7)S, and (59)T) located at the N-terminal region. Alanine substitution experiments with Mcm2 peptides showed that the phosphorylation of (5)S and (53)S by Cdc7 required the presence of an acidic amino acid adjacent to a serine residue. Furthermore, although Cdc7 was unable to phosphorylate a Mcm2 peptide (spanning amino acids 19-30 and containing (26)S and (27)S), it phosphorylated (26)S efficiently when this peptide contained a chemically synthesized phospho-(27)S modification. Hence, additional Cdc7 phosphorylation sites could be generated in Mcm2 by its prior phosphorylation by a cyclin-dependent kinase. This finding may explain why the sequential action of cyclin-dependent and Cdc7 kinases is essential for the initiation of DNA replication.

Amino Acid Sequence↗